PROC. ENT. SOC. WASH., VOL. 21, NO. 8, NOV., 1919 191 
able flight —the heaviest up till that time of the season. Two 
males of T. americanus were shot down during the flight at dawn ; 
as usual, no females were observed in the flight. 
On March 15 it was raining and there was no flight of T. amer- 
icanus. On March 16 it was cooler with high winds; on March 
17 there were high winds and no flight; fewer females of T. amer- 
icanus were in evidence, the weather being squally. The tem- 
perature on March IS was 68° F., and too cool for a flight; the 
numbers of females of T. americanus on tree trunks and screen 
were increasing. On March 19, it was cool and there was no 
flight, but numbers of females of T. americanus were increasing 
on the screens and in the woods. 
On March 21, the temperature was as low as 42° F. at day- 
break; there was no flight. March 22, with a temperature of 
only 58°, witnessed the heaviest flight of the season. However, 
the flight had not yet reached the full proportions of last season. 
Numerous female adults of T. flams were collected on this date. 
There was a slight rain in the afternoon. On March 23 there was 
a strong flight of Tabanus americanus. One female adult of T. 
trijunctus was collected on the veranda screen on this date. 
The dawn was clear and it was warm on March 24; there was 
a strong flight of T. americanus . One male of T. trijunctus was 
captured in the hammock. 
On April 2 the early morning flight of T. americanus was strong; 
three males were shot while hovering; all that have so far been 
shot have been males. By April 3 to 4 the flight seems to have 
reached its full height. 
On April 5, 6 and 7 the flight continued normal. 
April 8, 9 and 10 dawned with a heavy fog and no flight; on 
April 10 the males were feeding on flowers in the forest, keeping 
well in the shade during sunshine. 
On April 11 there was a bright dawn, and a strong flight — one 
of the loudest and strongest flights ever witnessed. 
From April 12 to 16 the flight continued to be strong (at its 
height); two adults were observed to strike in mid-air, descend- 
ing to the brush below, clasped; they escaped before their sex 
could be determined. 
On April 17 there were light showers at dawn; there was no 
flight. April 18 was cloudy and there was a very light flight of 
but few minutes’ duration. 
From April 19 to 21 there were moderate flights. Females 
were later seen on saw palmetto blossoms. 
On April 22 T. trijunctus was at the height of its season and 
adults were very annoying to both man and beast; the adults 
gathered in automobile tops, followed teams, etc. All work ani- 
192 PROC. ENT. SOC. WASH., VOL- 21, NO. S, NOV., 1919 
mals were covered with bagging for protection against these gad- 
flies. 
From April 23 to 30 the flight continued to be normal. On 
April 25 the screen door of the veranda was left open for two 
hours following sunrise and 60 T. americanus , 323 T. trijunctus } 
84 7 . Uneola and 3 T. flams female adults were captured. One 
female adult of T. turbidus was also captured. 
On May 1, after a heavy afternoon rain on April 30, there was 
one of the heaviest flights of the season. Rain seems to increase 
the flight. Evidently fresh adults were just emerging and could 
be heard trying out their wings. 
Normal flights occurred on May 2, 3, 4 and 5; the flights always 
being stronger on bright, fair dawns than on foggy, cloudy or 
misty mornings, the duration of the flight being governed by 
the rapidity of dawn. May 6-11 saw the flight decreasing in 
strength, females were in evidence but males were still numerous 
in the shade of the hammock. On May 5 a few female adults of 
T. flams were collected on the veranda screen. 
On May 12 there was a drizzling rain and no flight. May 13 
dawned foggy and the flight was very short and not as strong 
as usual. 
There was a normal flight on May 14, although the adults were 
decreasing in numbers; there was heavy rainfall in the evening 
and night. 
On May 15 there was a very light flight owing to the damp 
atmosphere. May 16 dawned clear but there was a perceptible 
waning of the flight of the large gadfly. The loud “roaring 
swarming” was past for the season but there were still “strag- 
glers” present in the hammock. While this flight lasted in 1919, 
it was even stronger than in former years. Other gadflies, Ta- 
banus trijunctus and T. Uneola , as well as “deerflies” (Chrysops ) , 
were still abundant and annoying. Mosquitoes were now pres- 
ent and also made life interesting. 
By May 17 the flight was declining in volume daily; the females 
were more abundant than the males. 
From the 18th to 22nd the flight was decreasing and was of 
very much shorter duration — lasting only 9 minutes on May 18. 
On the 23rd the flight was noted only over the densest portion 
of the hammock. 
There was a very small flight on May 24— only 3 adults were 
observed hovering and a few more were heard. 
During the week of May 25 to 31 there was no flight of T. 
americanus. An occasional male could still be observed on flow- 
ers and quite a few females were in evidence. T. Uneola adults 
were not so numerous. T. atratus was more in evidence than 
